Hey now, EVs are plenty important before Level 100. To give you an example, my EV spread on my Impish Diggersby is 4 HP / 252 Attack / 252 Speed, and it outspeeds the wild Tauros on Route 1. (For reference, Tauros has a base Speed of 110, while Diggersby has a base Speed of 78.) And it isn't grossly overleveled, either, My Diggersby is only Level 53, while the Tauros are Level 52.